High intensity exercise and experimental diabetes: influences of physical training on metabolic and endocrine aspects related to stress in rats

Abstract

The aims of this study were: 1) to verify the effects of high intensity physical training on metabolic and endocrine parameters in aloxan-diabetic rats; 2) to analyze the relationship between this exercise model with the stress response related to diabetes condition and intense physical training. Male young Wistar rats were distributed into 4 experimental groups: CS – sedentary control; CT – trained control; DS – sedentary diabetic; e DT – trained diabetic. Experimental diabetes was induced by intravenous aloxan administration (35mg/Kg of body weight). The physical training consisted of 4 sets of 10 jumps/day in a swimming pool, supporting a load that corresponded to 50% of body weight, 5 days/week, during 6 weeks. At the end of the 6th week, rats were sacrificed in rest condition to excise gastrocnemius muscle, epididymal fat, liver, heart and adrenal glands. Blood samples were used to determine serum glucose, insulin, corticotrophin (ACTH), corticosterone and lipids. Results indicated that physical training favored lipid profile, reducing total lipids, fatty free acids (FFA), total cholesterol and low-density lipoprotein in diabetic group. High intensity physical training also favored muscle metabolism, improving total muscle mass and muscular glycogen and protein in diabetic rats. Furthermore, physical training resulted in increased muscle DNA in both control and diabetic groups. Both training and diabetes condition did not change ACTH, corticosterone and adrenal cholesterol concentrations. However, physical training reduced adrenal hypertrophy produced by experimental diabetes. It was concluded that high intensity physical training favored glucose, protein and lipid metabolism, and resulted in positive responses to chronic stress in experimental diabetic rats. Key-words: diabetes, intense physical training, stress, metabolism.